This only works when the difficult drop rates are below miner leaving rates.
Which in normal times, are something taken for granted, but once it does happen, the edge case collapse the entire system.
edit: the earlier language is not exact, the scenario is an exponential drop of value that results in exponential drop in miner willing to mine until this discrepancy can be resolved. i.e. the system is not protected against extreme volatility (e.g. -99% over a block cycle)
Which in normal times, are something taken for granted, but once it does happen, the edge case collapse the entire system.
edit: the earlier language is not exact, the scenario is an exponential drop of value that results in exponential drop in miner willing to mine until this discrepancy can be resolved. i.e. the system is not protected against extreme volatility (e.g. -99% over a block cycle)